Of the four Cs which determine quality, diamond cut is the most complex to understand as well as the most important characteristic in choosing a diamond. The cut refers not only to the diamond’s proportions and symmetry, but also to the delicate crafting of each and every facet. The combination of these factors, together with the polish and overall finish is known as the cut of the diamond.
The cut of a diamond is often related to the final diamond shape but not always.
Diamond Vocabulary
To understand some of the finer points of diamond cuts, it’s necessary to first understand some basic diamond vocabulary.
Diameter: The width of the diamond from one side of the girdle to the other.
Table: The large facet (face) at the top of the diamond
Girdle: The edge of the diamond between the crown and the pavilion. the girdle is the area of the diamond with the largest circumference
Crown: The top part of the diamond from the girdle to the table
Culet: The minute facet on the bottom tip of the diamond
Pavilion: The part of the diamond from underneath the girdle to the culet
Depth: The diamond measurement from the table to the culet
Let the Light Shine Through
Every diamond has its own, unique proportions which directly affect the way light travels through the diamond and is reflected back up through the table. This, in turn, influences the sparkle, or brilliance, of the diamond and its perceived beauty. In fact, the cut of a diamond, far more than its color or clarity, affects its splendor. If a diamond is cut too shallow, light can escape from underneath, reducing the brilliance. If the cut is too deep, light can spread out from the sides, again affecting the sparkle. A diamond with good proportions will allow the light to travel inside the diamond, reflecting the light through the table and crown for maximum sparkle.
The sparks or small flashes of light often seen as a diamond moves are otherwise known as scintillation. As well as brilliance, which is essentially the amount of white light reflected by the diamond, the cut also influences the amount of fire and scintillation of the diamond. The fire is the way the light is refracted by the diamond, splitting it into the beautiful colors of the rainbow.